@techreport{TR-IC-98-01,
  number = {IC-98-01},
  author = {Pinto, Guilherme A. and de Rezende, Pedro J.},
  title = {Representing Conics using the Oriented Projective Plane},
  month = {January},
  year = {1998}, 
  institution = {Institute of Computing, University of Campinas},
  note = {In English, 7 pages.
    \par\selectlanguage{english}\textbf{Abstract}
      We present a geometric definition of conic sections in the
      oriented projective plane and describe some of their nice
      properties.  The three main classes of affine conics are unified
      by a generalized distance notion on that space.  This definition
      leads to a very simple representation of conic arcs suitable for
      implementations of geometric solutions to problems involving the
      concept of distance, in particular, the construction of various
      generalizations of Voronoi diagrams.
  }
}